dc jacks have usually 3 pins, there are two ways to unsolder it, you can either try to heat all 3 pads so that you can pick it up with a tweezer, or you heat up one pad and lift it with a little bit of force, then heat the next pad until its out, if it has 3 pins use the second way as its much easier for first time solderers.
if it has just 2 pins just heat both pads and take it out.
be careful the dc jack gets very hot








